I always have my firewall block my offline games from this site. today i seen a game I bought on this site (severed steel) shows me a halloween daily challange in the main menu. I believed that maybe the game just read the clock on my PC but When I unplugged my modem the daily challange was replaced with a retry massage.
That means that the daily challanges need online connection, but how did it get it?
The game is blocked by windows 10 firewall. is the firewall not working? is the game somehow able to bypass it?

Can anyone please help me?

The daily challenges require an internet connection.
Have you installed it through the Galaxy client ? If yes , then maybe the game using that connection to communicate with the server .

Not only is it possible for installers to add a Windows Firewall exception, but this is the practice recommended by Microsoft: "Make the firewall configuration seamless for your users. Add your application to the exception list during installation".
This is usually presented in the form of an option to check during installation. It's possible GOG's offline installers just do it without asking.

Double-check your Windows Firewall settings and make sure the actual game executable is blocked. Sometimes there are several.

On Windows 11, my firewall automatically creates a rule and allows the connection. Why? Because it's crippled compared to former versions. Microsoft did it dirty on this one.

okay, I fixed the problem. I have no idea why it worked.
I had the firewall block the file that the shortcut is leading to.
HARD_DRIVE\GOG Games\Severed Steel\ThankYouVeryCool.exe
that did not stop the daily challange from appearing, I found another file in the game folder
HARD_DRIVE\GOG Games\Severed Steel\ThankYouVeryCool\Binaries\Win64\ThankYouVeryCool-Win64-Shipping.exe
and made a firewall command to block that too, that worked.
I disabled the block on the second file, the daily challange comes back. I enable it again and the daily disappear again.
I am happy that I found a fix but I am worried. I found a fix by blindly guessing, how could I have known one EXE was activating the second? and how many of the games on GOG can connect online even if I block the file the desktop shortcut leads to?

By the way, I never installed the Galaxy client

That maybe a bigger rabbit hole than one expect.

Many games nowadays use several API that may connect by some reason (most likely telemetry) and the most used engines, both Unreal and Unity have a metric ton of built in telemetry.

Unreal can call "CrashReportClient.exe" or UnrealCEFSubProcess.exe" inside bin folder, while Unity call "UnityCrashHandler64.exe". There are probably other modules depending on the game.

The way I used to do is to search the game folder by ".exe" files and block them all, at some point I got tired and setup the OS to block everything by default but some games do create an exception (probably because of multiplayer). Worth noting that the games that created an exception were from Steam, never saw it from GOG offline installers but my installed games library is limited. (and also because I rerely install games, just copy the "installed" folder)

At this point I just pull the Ethernet cable when playing games and use internet on another computer.

I looked on youtube for "how to block an entire folder windows defender guide".
I found a video instructing to write a few lines of code in a ".txt" file and changing it to ".bat"
I am no programer so I am a bit fearful of trusting that video blindly, I will ask on a few forums to review the video if I get answers I will report here again